Health alert after infectious teen visits Dreamworld

Since August, 21 cases of measles have been confirmed in Queensland and the state's chief health officer Dr Jeannette Young has warned anyone who visited Dreamworld on October 2 had potentially been exposed to the virus.

"Measles is the most highly contagious virus known to man," she said.

"If you are exposed and not protected, you will get infected."

North Coast Public Health Unit said one person living in the Byron Bay area had been diagnosed with measles after visiting both Tweed Hospital and Byron District Hospital.

It is not known if the Byron Bay person diagnosed with measles is the same person who visited Dreamworld.

North Coast public health assistant director Greg Bell said those who are not immunised are heightening the risk of contracting the highly infectious virus.

"Measles is spread through coughing and sneezing. Symptoms can include fever, tiredness, runny nose, cough and sore red eyes, which usually lasts for several days before a red blotchy rash appears. Complications range from an ear infection and diarrhoea, through to pneumonia and swelling of the brain (encephalitis)," he said.

People born during or after 1966 who don't have two documented doses of MMR vaccine should contact their local health provider for vaccination advice. People born before 1966 are usually immune because they had measles during childhood. The MMR vaccine is free to people born during or after 1966.

"The time from exposure to the onset of symptoms is typically 8 to 18 days. People are infectious 4-5 days before onset of the rash and 4-5 days after appearance of the rash," Mr Bell said.

"Anyone who contracts measles should stay away from work, preschool, school and other public places until at least 4 days after the onset of the rash, when they are no longer infectious."

Measles in the area is particularly worrying, as one in ten children in the Richmond-Tweed region are not immunised, according to the Australian Childhood Immunisation Register.

Low immunisation rates across the Tweed could make it a prime target for the spread of infectious diseases.

There is a rate of 9.9% vaccine refusals in the Richmond Tweed set against a national average of 1.5%.